Cascaded standardized hot-pluggable transceiving units providing a multiviewer functionality

ABSTRACT

A system comprising cascaded standardized hot-pluggable transceiving units for providing a multiviewer functionality. A first layer comprises a plurality of transceiving units implementing a scaling functionality followed by a pre-positioning functionality. A second layer comprises a transceiving unit implementing a positioning functionality. Source video streams are scaled by the first layer, and further combined to generate primary mosaiced video streams. The primary mosaiced video streams are combined by the second layer to generate a secondary mosaiced video stream. Alternatively, the first layer comprises at least one transceiving unit only implementing the scaling functionality. Source video streams are scaled by the first layer to generate scaled video streams. The scaled video streams are combined by the second layer to generate a mosaiced video stream.

TECHNICAL FIELD

The present disclosure relates to the field of standardizedhot-pluggable transceiving units. More specifically, the presentdisclosure relates to cascaded standardized hot-pluggable transceivingunits providing a multiviewer functionality.

BACKGROUND

Small Form-factor Pluggable (SFP) units represent one example ofstandardized hot-pluggable transceiving units. SFP units arestandardized units adapted to be inserted within a chassis. A suite ofspecifications, produced by the SFF (Small Form Factor) Committee,describe the size of the SFP unit, so as to ensure that all SFPcompliant units may be inserted smoothly within one same chassis, i.e.inside cages, ganged cages, superposed cages and belly-to-belly cages.Specifications for SFP units are available at the SFF Committee website.

SFP units may be used with various types of exterior connectors, such ascoaxial connectors, optical connectors, RJ45 connectors and variousother types of electrical connectors. In general, an SFP unit allowsconnection between an external apparatus, via a front connector of oneof the aforementioned types, and internal components of a hosting unit,for example a motherboard, a card or a backplane leading to furthercomponents, via a back interface of the SFP unit. Specification noINF-8074i Rev 1.0, entitled “SFP (Small Form-factor Pluggable)Transceiver, dated May 12, 2001, generally describes sizes, mechanicalinterfaces, electrical interfaces and identification of SFP units.

The SFF Committee also produced specification no SFF-8431 Rev. 4.1,“Enhanced Small Form-factor Pluggable Module SFP+”, dated Jul. 6, 2010.This document, which reflects an evolution of the INF-8074ispecification, defines, inter alia, high speed electrical interfacespecifications for 10 Gigabit per second SFP+ modules and hosts, andtesting procedures. The term “SFP+” designates an evolution of SFPspecifications.

INF-8074i and SFF-8431 do not generally address internal features andfunctions of SFP devices. In terms of internal features, they simplydefine identification information to describe SFP devices' capabilities,supported interfaces, manufacturer, and the like. As a result,conventional SFP devices merely provide connection means betweenexternal apparatuses and components of a hosting unit, the hosting unitin turn exchanging signals with external apparatuses via SFP devices.

Recently, SFP units with internal features and functions providingsignal processing capabilities have appeared. For instance, some SFPunits now include signal re-clocking, signal reshaping orreconditioning, signals combination or separation, signal monitoring,etc.

In the field of video transport, advances have been made recently fortransporting the payload of a video signal into Internet Protocol (IP)packets (e.g. Serial Digital Interface (SDI) video payloads encapsulatedinto IP packets). Furthermore, an SFP unit can be adapted to receive theIP flows transporting the video payloads, and to process the videopayloads.

One issue with the transport of video IP flows on an IP networkinginfrastructure is that video IP flows generally require a subsequentamount of bandwidth (which can lead to network congestion), and are verysensitive to delays. The currently deployed IP based video distributioninfrastructures do not always make usage of the available bandwidth inan optimized manner.

For example, a plurality of source video streams is transported at fullresolution via a corresponding plurality of video IP flows. An equipment(e.g. a multiviewer) receives the plurality of source video streamstransmitted at full resolution, scales down the plurality of sourcevideo streams to a lower resolution, further combines the plurality ofscaled video streams into a mosaiced video stream, and displays themosaiced video stream into a monitoring window. The plurality of sourcevideo streams is transported at full resolution from their source to thedestination equipment (e.g. the multiviewer), which represents asignificant load burden on the underlying IP networking infrastructure.A more efficient way to proceed would be to implement the multiviewerfunctionality (the combination of the scaling and mosaicingsub-functionalities) at an intermediate equipment, such as an IP switchor a router, to save bandwidth between the intermediate equipment andthe destination equipment. However, current IP switches or routers arenot adapted for implementing the multiviewer functionality (thecombination of the scaling and mosaicing sub-functionalities).

Therefore, there is a need for a new system comprising cascadedstandardized hot-pluggable transceiving units providing a multiviewerfunctionality.

SUMMARY

According to a first aspect, the present disclosure provides a systemcomprising a plurality of primary standardized hot-pluggabletransceiving units and a secondary standardized hot-pluggabletransceiving unit. The plurality of primary transceiving unitsrespectively comprises a housing having specific standardized dimensionsand adapted to being inserted into a chassis of a hosting unit. Theplurality of primary transceiving units respectively comprises at leastone connector for receiving a plurality of source video streams. Theplurality of primary transceiving units respectively comprises at leastone processing unit in the housing for scaling the plurality of sourcevideo streams into a corresponding plurality of scaled video streams,mosaicing the plurality of scaled video streams into a primary mosaicedvideo stream, and outputting the primary mosaiced video stream via oneof: the at least one connector or another connector of the plurality ofprimary transceiving units. The secondary transceiving unit comprises ahousing having specific standardized dimensions and adapted to beinginserted into a chassis of a hosting unit. The secondary transceivingunit comprises at least one connector for receiving the primary mosaicedvideo streams from the plurality of primary transceiving units. Thesecondary transceiving unit comprises at least one processing unit inthe housing for mosaicing the primary mosaiced video streams into asecondary mosaiced video stream, and outputting the secondary mosaicedvideo stream via one of: the at least one connector or another connectorof the secondary transceiving unit.

According to a second aspect, the present disclosure provides a systemcomprising at least one primary standardized hot-pluggable transceivingunit and a secondary standardized hot-pluggable transceiving unit. Theat least one primary transceiving unit comprises a housing havingspecific standardized dimensions and adapted to being inserted into achassis of a hosting unit. The at least one primary transceiving unitcomprises at least one connector for receiving a plurality of sourcevideo streams. The at least one primary transceiving unit comprises atleast one processing unit in the housing for scaling the plurality ofsource video streams into a corresponding plurality of scaled videostreams, and outputting the plurality of scaled video streams via oneof: the at least one connector or another connector of the at least oneprimary transceiving unit. The secondary transceiving unit comprises ahousing having specific standardized dimensions and adapted to beinginserted into a chassis of a hosting unit. The secondary transceivingunit comprises at least one connector for receiving the plurality ofscaled video streams from the at least one primary transceiving unit.The secondary transceiving unit comprises at least one processing unitin the housing for mosaicing the plurality of scaled video streams intoa mosaiced video stream, and outputting the mosaiced video stream viaone of: the at least one connector or another connector of the secondarytransceiving unit.

According to a third aspect, the present disclosure provides a systemcomprising a plurality of primary standardized hot-pluggabletransceiving units and a secondary standardized hot-pluggabletransceiving unit. The plurality of primary transceiving unitsrespectively comprises a housing having specific standardized dimensionsand adapted to being inserted into a chassis of a hosting unit. Theplurality of primary transceiving units respectively comprises at leastone connector for receiving a plurality of scaled video streams. Theplurality of primary transceiving units respectively comprises at leastone processing unit in the housing for mosaicing the plurality of scaledvideo streams into a primary mosaiced video stream, and outputting theprimary mosaiced video stream via one of: the at least one connector oranother connector of the plurality of primary transceiving units. Thesecondary transceiving unit comprises a housing having specificstandardized dimensions and adapted to being inserted into a chassis ofa hosting unit. The secondary transceiving unit comprises at least oneconnector for receiving the primary mosaiced video streams from theplurality of primary transceiving units. The secondary transceiving unitcomprises at least one processing unit in the housing for mosaicing theprimary mosaiced video streams into a secondary mosaiced video stream,and outputting the secondary mosaiced video stream via one of: the atleast one connector or another connector of the secondary transceivingunit.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure will be described by way of example onlywith reference to the accompanying drawings, in which:

FIG. 1 is a top view of an SFP unit;

FIG. 2 is a side elevation view of the SFP unit of FIG. 1;

FIG. 3 is a front elevation view of the SFP unit of FIG. 1;

FIG. 4 is back elevation view of the SFP unit of FIG. 1;

FIG. 5 is a bottom view of the SFP unit of FIG. 1;

FIG. 6 is a perspective view of the SFP unit of FIG. 1;

FIG. 7 represents a first implementation of a system comprising cascadedstandardized hot-pluggable transceiving units for providing amultiviewer functionality;

FIG. 8A illustrates a scaling functionality implemented by the system ofFIG. 7;

FIG. 8B illustrates a pre-positioning functionality implemented by thesystem of FIG. 7;

FIG. 8C illustrates a positioning functionality implemented by thesystem of FIG. 7;

FIGS. 9A and 9B illustrate a primary SFP unit of the system of FIG. 7;

FIGS. 10A, 10B and 100 illustrate a secondary SFP unit of the system ofFIG. 7;

FIG. 11 represents a second implementation of a system comprisingcascaded standardized hot-pluggable transceiving units for providing amultiviewer functionality;

FIG. 12A illustrates a scaling functionality implemented by the systemof FIG. 11;

FIG. 12B illustrates a positioning functionality implemented by thesystem of FIG. 11;

FIGS. 13A and 13B illustrate a primary SFP unit of the system of FIG.11;

FIGS. 14A, 14B and 14C illustrate a secondary SFP unit of the system ofFIG. 11;

FIG. 15 illustrates an exemplary use case for the usage of the systemrepresented in FIG. 7;

FIG. 16 represents an alternative to the first implementationrepresented in FIG. 7 of a system comprising cascaded standardizedhot-pluggable transceiving units for providing a multiviewerfunctionality; and

FIG. 17 represents an alternative to the second implementationrepresented in FIG. 11 of a system comprising cascaded standardizedhot-pluggable transceiving units for providing a multiviewerfunctionality.

DETAILED DESCRIPTION

The foregoing and other features will become more apparent upon readingof the following non-restrictive description of illustrative embodimentsthereof, given by way of example only with reference to the accompanyingdrawings.

The present disclosure describes standardized hot-pluggable transceivingunits, such as Small Form-factor Pluggable (SFP)/SFP+ units, havinginternal features that far exceed those of conventional units. Whileconventional units merely provide connection capabilities between ahosting unit in which they are inserted and external apparatuses, thestandardized hot-pluggable transceiving units disclosed herein providethe capability of processing and combining received video streams, inorder to generate a resulting mosaiced video stream for display on amultiviewer.

The following terminology is used throughout the present disclosure:

-   -   SFP: Small Form-factor Pluggable, this term refers to units that        are insertable into a chassis of a hosting unit; in the present        disclosure, an SFP unit complies with an industry standard        specification.    -   Connector: A device component for physically joining circuits        carrying electrical, optical, radio-frequency, or like signals.    -   Video signal: Analog or digital signal usable for display        purposes, either directly on a monitor, or through multicast or        broadcast.

In the rest of the disclosure, an SFP unit is used to illustrate anexample of a standardized hot-pluggable transceiving unit. However, theteachings of the present disclosure are not limited to an SFP unit, andcan be applied to any type of standardized hot-pluggable transceivingunit.

An SFP unit comprises a housing having a front panel, a back panel, atop, a bottom and two sides. Generally, the front panel includes atleast one front connector for connecting a cable, a fiber, twistedpairs, etc. The back panel includes at least one rear connector forconnecting to a hosting unit. However, as will be illustrated later inthe present disclosure, the SFP unit may have no front connector, oralternatively no rear connector. The SFP unit may be fully-compliant orpartially compliant with standardized SFP dimensions, such as SFP, SFP+,XFP (SFP with 10 Gigabit/s data rate), Xenpak, QSFP (Quad (4-channel)SFP with 4×10 Gigabit/s data rate), QSFP+, CFP (C form-factor pluggablewith 100 Gigabit/s data rate), CPAK or any other standardized SmallForm-factor Pluggable unit. Consequently, in the context of the presentdisclosure, an SFP unit may correspond to SFP, SFP+, XFP, Xenpak, QSFP,QSFP+, CFP, CPAK, or any other known standards related to SmallForm-factor Pluggable units.

Reference is now made concurrently to FIGS. 1-6, which are,respectively, a top view, a side elevation view, a front elevation view,a back elevation view, a bottom view and a perspective view of an SFPunit 10. The SFP unit 10 comprises a housing 12. The housing defines atop 14, a bottom 24, and two sides 22. The housing 12 may be at leastpartially of dimensions in compliance with at least one of the followingstandards: SFP, SFP+, XFP, Xenpak, QSFP, QSFP+, CFP, CPAK, etc.Alternatively, the housing 12 has functional dimensions based on atleast one of the following standards: SFP, SFP+, XFP, Xenpak, QSFP,QSFP+, CFP, CPAK, etc.

The SFP unit 10 further comprises a back panel 16 affixed to the housing12. The back panel 16 comprises a rear connector 17, for instance anelectrical or an optical connector. In an example, the back panelcomprises the rear connector 17 (also named a host connector) suitableto connect the SFP unit 10 to a backplane of a chassis (not shown forclarity purposes) of a hosting unit, as known to those skilled in theart.

The SFP unit 10 further comprises a front panel 18 affixed to thehousing 12. The front panel 18 comprises one or more connectors, forexample a connector 20 of a co-axial cable type such as SDI, adapted tosend and/or receive a digital video signal and a connector 21, also ofthe co-axial cable type, adapted to send and/or receive a digital datasignal. The SFP unit 10 further comprises an engagement mechanism, suchas for example a latch 26 as shown in a resting position on the bottom24 in FIG. 2, for maintaining the SFP unit 10 in place within a chassis.

Referring now to FIG. 7, a first implementation of a system comprisingcascaded standardized hot-pluggable transceiving units for providing amultiviewer functionality is represented. As mentioned previously, forillustration purposes, the standardized hot-pluggable transceiving unitsconsist of SFP units; but other types of standardized hot-pluggabletransceiving units may be used for implementing the system.

The system comprises a plurality of primary SFP units 200, and asecondary SFP unit 300. For illustration purposes, four primary SFPunits 200 are represented in FIG. 7. However, the number of primary SFPunits 200 used by the system may vary. The first layer comprising theplurality of primary SFP units 200 is cascaded into the second layercomprising the secondary SFP unit 300.

Each one of the plurality of primary SFP units 200 receives a pluralityof source video streams 201, which are processed by the primary SFP unit200 to generate and output a primary mosaiced video stream 211. Forillustration purposes, four source video streams 201 are received byeach primary SFP unit 200 in FIG. 7. However, the number of source videostreams 201 received by each primary SFP unit 200 may vary, and maydiffer from one primary SFP unit 200 to another. As will be illustratedlater in the description, each primary SFP unit 200 implements a scalingfunctionality and a pre-positioning functionality for generating theoutputted primary mosaiced video stream 211 based on the received sourcevideo streams 201.

The secondary SFP unit 300 receives the plurality of primary mosaicedvideo stream 211 generated and outputted by the plurality of primary SFPunits 200. The secondary SFP unit 300 processes the plurality of primarymosaiced video stream 211 to generate and output a secondary mosaicedvideo stream 311. As will be illustrated later in the description, thesecondary SFP unit 300 implements a positioning functionality forgenerating the outputted secondary mosaiced video stream 311 based onthe received primary mosaiced video streams 211.

Reference is now made concurrently to FIGS. 7, 8A, 8B and 8C; where FIG.8A illustrates the scaling functionality implemented by the primary SFPunits 200, FIG. 8B illustrates the pre-positioning functionalityimplemented by the primary SFP units 200, and FIG. 8C illustrates thepositioning functionality implemented by the secondary SFP unit 300.

Referring more particularly to FIGS. 7 and 8A, the source video streams201 received by the primary SFP unit 200 located on the left of FIG. 7are respectively labelled A1, A2, A3 and A4. The scaling functionalityimplemented by the primary SFP unit 200 scales the source video streamsA1, A2, A3 and A4 into corresponding scaled video streams respectivelylabelled A′1, A′2, A′3 and A′4. FIG. 8A illustrates a horizontal scalingfactor of ½ and a vertical scaling factor of ½ applied to the sourcevideo streams A1, A2, A3 and A4 to generate the scaled video streamsA′1, A′2, A′3 and A′4. FIG. 8A is for illustration purposes only.Different values of scaling factors may be applied to each one of thesource video streams (e.g. A1, A2, A3 and A4) received by each one ofthe plurality of primary SFP units 200, and the values of the scalingfactors may differ from one source video stream to another.

The operation consisting in scaling a source video stream into acorresponding scaled video stream is well known in the art. The sourcevideo stream transports a plurality of source video frames and thecorresponding scaled video stream transports a corresponding pluralityof scaled video frames. For each source video frame, a correspondingscaled video frame is generated. The generation of the scaled videostream comprises generating the plurality of scaled video frames byapplying the scaling ratio to the corresponding plurality of sourcevideo frames.

Additional data (e.g. an audio payload, a metadata payload, acombination thereof, etc.) included in the source video stream, and notconsisting of the source video frames, are included into the scaledvideo stream, and optionally modified if appropriate. The metadatapayload comprises at least one of the following: closed caption text,subtitle text, rating text, a time code (e.g. for indicating a timeinterval before a program goes live), a Vertical Blanking Interval(VBI), V-chip rating, etc. Alternatively, the audio payload and/or themetadata payload are transported independently of the video streams, andare not processed by the scaling functionality. Furthermore, additionalinformation related to the scaling operation not included in the sourcevideo stream may be included in the scaled video stream (for instance,the value of the scaling ratio).

Various scaling ratios can be applied by the scaling functionality. Inparticular, the scaling ratio consists of a single ratio applied to boththe length and the width of the plurality of source video frames.Alternatively, the scaling ratio consists of a combination of ahorizontal ratio and a vertical ratio applied respectively to the lengthand the width of the plurality of source video frames. The values of thesingle ratio, horizontal ratio and vertical ratio are generallyexpressed as 1/N where N is an integer.

For example, if the source video stream transports source video frameshaving a resolution of 1024×1024 and the scaling ratio is a single ratioof ½, the scaled video stream comprises scaled video frames having aresolution of 512×512. If the scaling ratio comprises a horizontal ratioof ½ and a vertical ratio of ¼, the scaled video stream comprises scaledvideo frames having a resolution of 512×256.

The scaling operation is also usually referred to as spatial scaling,and consists in reducing the number of pixels in the source video framesto generate the scaled video frames, so that the bandwidth required fortransmitting the scaled video frames is reduced accordingly. Forinstance, a basic algorithm for applying a scaling ratio comprising ahorizontal ratio of ½ and a vertical ratio of ¼ consists in keepingevery two pixels in the lines of the source video frames and every 4pixels in the columns of the source video frames. More sophisticatedalgorithms can be implemented for preserving the quality of theresulting scaled video frames.

Alternatively or complementarily, the scaling operation may also consistin a temporal scaling. For instance, if the multiviewer functionalityimplemented by the system represented in FIG. 7 is used just forconfidence monitoring, and does not need to be fluid and to operate inreal time, the frame rate is scaled down instead of applying a spatialscaling, and a few images per second are transmitted instead of a realtime frame rate of 50-60 images per second.

Referring more particularly to FIGS. 7 and 8B, the pre-positioningfunctionality of each primary SFP unit 200 processes the plurality ofscaled video streams to generate the corresponding primary mosaicedvideo streams. The primary mosaiced video streams generated by the fourprimary SFP units 200 of FIG. 7 are respectively labelled A, B, C and D.FIG. 8B illustrates the positioning of the four scaled video streamsA′1, A′2, A′3 and A′4 generated by the first primary SFP unit 200 ofFIG. 7 to generate the corresponding primary mosaiced video stream A,the positioning of the four scaled video streams B′1, B′2, B′3 and B′4generated by the second primary SFP unit 200 of FIG. 7 to generate thecorresponding primary mosaiced video stream B, the positioning of thefour scaled video streams C′1, C′2, C′3 and C′4 generated by the thirdprimary SFP unit 200 of FIG. 7 to generate the corresponding primarymosaiced video stream C, and the positioning of the four scaled videostreams D′1, D′2, D′3 and D′4 generated by the fourth primary SFP unit200 of FIG. 7 to generate the corresponding primary mosaiced videostream D. The scaled video streams are not represented in FIG. 7 forsimplification purposes.

The operation consisting in generating a mosaiced video stream based ona plurality of scaled video streams is well known in the art. Each oneof the plurality of scaled video streams transports a plurality ofscaled video frames and the corresponding mosaiced video streamtransports a corresponding plurality of mosaiced video frames. Eachmosaiced video frame is generated by combining scaled video framesrespectively transported by each one of the plurality of scaled videostreams at respective given positions within the mosaiced video frame.For instance, FIG. 8B illustrates the mosaiced video frames A generatedby combining the scaled video frames A′ 1, A′2, A′3, A′4, these scaledvideo frames being respectively positioned at the upper left, upperright, lower left and lower right positions within mosaiced video framesA.

Additional data (e.g. an audio payload, a metadata payload, acombination thereof, etc.) included in the scaled video streams, and notconsisting of the scaled video frames, are included into the mosaicedvideo stream, and optionally modified if appropriate. The metadatapayload comprises at least one of the following: closed caption text,subtitle text, rating text, a time code (e.g. for indicating a timeinterval before a program goes live), a Vertical Blanking Interval(VBI), V-chip rating, etc. Alternatively, the audio payload and/or themetadata payload are transported independently of the video streams, andare not processed by the pre-positioning functionality. Furthermore,additional information related to the pre-positioning operation notincluded in the scaled video streams may be included in the mosaicedvideo stream (for instance, an identification of the scaled videostreams and their respective position within the mosaiced video stream).

Referring more particularly to FIGS. 7 and 8C, the positioningfunctionality of the secondary SFP unit 300 processes the plurality ofprimary mosaiced video streams A, B, C and D outputted by the pluralityof primary SFP units 200, to generate the secondary mosaiced videostream labelled E. FIG. 8C illustrates the positioning of the fourprimary mosaiced video streams A, B, C and D outputted by the primarySFP units 200 of FIG. 7 to generate the corresponding secondary mosaicedvideo stream E.

The operation consisting in generating the secondary mosaiced videostream based on the plurality of primary mosaiced video streams isfunctionally equivalent to the previously described operation consistingin generating each primary mosaiced video stream based on the pluralityof scaled video streams.

For instance, FIG. 8C illustrates the mosaiced video frames E generatedby combining the scaled video frames A, B, C, D; these scaled videoframes being respectively positioned at the upper right, lower left,lower right and upper left positions within the mosaiced video frames E.

Reference is now made concurrently to FIGS. 7, 8A, 8B and 9A; where FIG.9A illustrates a first configuration of the primary SFP unit 200. Theprimary SFP unit 200 corresponds to the SFP unit 10 represented in FIGS.1 to 6, and comprises the housing 12, the back panel 16 and the frontpanel 18.

The primary SFP unit 200 has a rear connector 17 on the back panel 16,and receives the source video streams 201 (A1, A2, A3 and A4) via therear connector 17.

The primary SFP unit 200 comprises at least one processing unit 250(only one processing unit 250 is represented on FIG. 9A forsimplification purposes). The at least one processing unit 250 executesthe aforementioned scaling functionality 252 and pre-positioningfunctionality 254.

The scaling functionality 252 processes the received source videostreams A1, A2, A3 and A4 for respectively scaling the source videostreams A1, A2, A3 and A4 into the scaled video streams A′1, A′2, A′3and A′4.

The pre-positioning functionality 254 processes the scaled video streamsA′1, A′2, A′3 and A′4 for mosaicing the scaled video streams A′1, A′2,A′3 and A′4 into the primary mosaiced video stream 211 (A). The primarymosaiced video stream 211 (A) is outputted via the rear connector 17.

The primary SFP unit 200 does not have any front connector on the frontpanel 18, since all the data are exchanged via the rear connector 17.Alternatively, the primary SFP unit 200 may have one or more frontconnectors on the front panel 18, for exchanging additional data andperforming a processing of these additional data which is out of thescope of the present disclosure.

Reference is now made concurrently to FIGS. 7, 8A, 8B and 9B; where FIG.9B illustrates a second configuration of the primary SFP unit 200. Theprimary SFP unit 200 corresponds to the SFP unit 10 represented in FIGS.1 to 6, and comprises the housing 12, the back panel 16 and the frontpanel 18.

The primary SFP unit 200 has a rear connector 17 on the back panel 16and a front connector 20 on the front panel 18. The primary SFP unit 200receives the source video streams 201 (A1, A2, A3 and A4) via the frontconnector 20.

The primary SFP unit 200 comprises at least one processing unit 250(only one processing unit 250 is represented on FIG. 9B forsimplification purposes). The at least one processing unit 250 executesthe aforementioned scaling functionality 252 and pre-positioningfunctionality 254.

The scaling functionality 252 processes the received source videostreams A1, A2, A3 and A4 for respectively scaling the source videostreams A1, A2, A3 and A4 into the scaled video streams A′1, A′2, A′3and A′4.

The pre-positioning functionality 254 processes the scaled video streamsA′1, A′2, A′3 and A′4 for mosaicing the scaled video streams A′1, A′2,A′3 and A′4 into the primary mosaiced video stream 211 (A). The primarymosaiced video stream 211 (A) is outputted via the rear connector 17.Alternatively, the primary mosaiced video stream 211 (A) is outputtedvia the front connector 20 (this configuration is not represented in theFigures for simplification purposes).

The primary SFP unit 200 may have more than one front connector on thefront panel 18 (this configuration is not represented in the Figures forsimplification purposes). The reception of the source video streams 201is spread across the plurality of front connectors. For example, thefront connector 20 receives the source video streams A1 and A2, and asecond front connector not represented in FIG. 9B receives the sourcevideo streams A3 and A4. Alternatively, the front connector 20 receivesall the source video streams A1, A2, A3 and A4 as illustrated in FIG.9B, and a second front connector not represented in FIG. 9B outputs theprimary mosaiced video stream 211 (A).

In a particular embodiment, the primary SFP unit 200 has four frontconnectors (Quad SFP) of electrical or optical type with an aggregatebandwidth of at least 40 Gbps.

Reference is now made concurrently to FIGS. 7, 8C and 10A; where FIG.10A illustrates a first configuration of the secondary SFP unit 300. Thesecondary SFP unit 300 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 300 has a rear connector 17 on the back panel 16,and receives the primary mosaiced video streams 211 (A, B, C and D) viathe rear connector 17.

The secondary SFP unit 300 comprises at least one processing unit 350(only one processing unit 350 is represented on FIG. 10A forsimplification purposes). The at least one processing unit 350 executesthe aforementioned positioning functionality 352.

The positioning functionality 352 processes the primary mosaiced videostreams 211 (A, B, C and D) for mosaicing the primary mosaiced videostreams 211 (A, B, C and D) into the secondary mosaiced video stream 311(E). The secondary mosaiced video stream 311 (E) is outputted via therear connector 17.

The secondary SFP unit 300 does not have any front connector on thefront panel 18, since all the data are exchanged via the rear connector17. Alternatively, the secondary SFP unit 300 may have one or more frontconnectors on the front panel 18, for exchanging additional data andperforming a processing of these additional data which is out of thescope of the present disclosure.

Reference is now made concurrently to FIGS. 7, 8C and 10B; where FIG.10B illustrates a second configuration of the secondary SFP unit 300.The secondary SFP unit 300 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 300 has a rear connector 17 on the back panel 16,and a front connector 20 on the front panel 18. The secondary SFP unit300 receives the primary mosaiced video streams 211 (A, B, C and D) viathe rear connector 17.

The secondary SFP unit 300 comprises at least one processing unit 350(only one processing unit 350 is represented on FIG. 10A forsimplification purposes). The at least one processing unit 350 executesthe aforementioned positioning functionality 352.

The positioning functionality 352 processes the primary mosaiced videostreams 211 (A, B, C and D) for mosaicing the primary mosaiced videostreams 211 (A, B, C and D) into the secondary mosaiced video stream 311(E). The secondary mosaiced video stream 311 (E) is outputted via thefront connector 20.

The secondary SFP unit 300 may have more than one front connector on thefront panel 18, for exchanging additional data and performing aprocessing of these additional data which is out of the scope of thepresent disclosure.

Reference is now made concurrently to FIGS. 7, 8C and 10C; where FIG.10C illustrates a third configuration of the secondary SFP unit 300. Thesecondary SFP unit 300 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 300 has a rear connector 17 on the back panel 16and a front connector 20 on the front panel 18. The secondary SFP unit300 receives the primary mosaiced video streams 211 (A, B, C and D) viathe front connector 20.

The secondary SFP unit 300 comprises at least one processing unit 350(only one processing unit 350 is represented on FIG. 10C forsimplification purposes). The at least one processing unit 350 executesthe aforementioned positioning functionality 352.

The positioning functionality 352 processes the primary mosaiced videostreams 211 (A, B, C and D) for mosaicing the primary mosaiced videostreams 211 (A, B, C and D) into the secondary mosaiced video stream 311(E). The secondary mosaiced video stream 311 (E) is outputted via therear connector 17. Alternatively, the secondary mosaiced video stream311 (E) is outputted via the front connector 20 (this configuration isnot represented in the Figures for simplification purposes).

The secondary SFP unit 300 may have more than one front connector on thefront panel 18 (this configuration is not represented in the Figures forsimplification purposes). The reception of the primary mosaiced videostreams 211 is spread across the plurality of front connectors. Forexample, the front connector 20 receives the primary mosaiced videostreams A and B, and a second front connector not represented in FIG.10C receives the primary mosaiced video streams C and D. Alternatively,the front connector 20 receives all the primary mosaiced video streamsA, B, C and D as illustrated in FIG. 10C, and a second front connectornot represented in FIG. 10C outputs the secondary mosaiced video stream311 (E).

Referring more specifically to FIG. 7, an alternative implementation ofthe system consists of the following. The source video streams 201 arealready scaled, and the primary SFP units 200 only implement thepre-positioning functionality directly applied to the received sourcescaled video streams 201.

In another alternative implementation of the system, the functionalitiesof the secondary SFP unit 300 are implemented by a generic computingdevice (such as a computer, a server, a networking equipment, etc.)instead of a SFP unit.

Referring more specifically to FIGS. 7 and 16, still another alternativeimplementation of the system consists of the following. One of theprimary SFP units 200 represented in FIG. 7 also implements thefunctionalities of the secondary SFP unit 300 represented in FIG. 7.

FIG. 16 represents the SFP unit 200′ combining the functionalities of aprimary SFP unit (scaling functionality 252 and pre-positioningfunctionality 254 represented in FIG. 9A) and a secondary SFP unit(positioning functionality 352 represented in FIG. 10). The SFP unit200′ receives the source video streams 201, which are processed by thescaling functionality 252 and the pre-positioning functionality 254represented in FIG. 9A to generate an internal primary mosaiced videostream (not represented in FIG. 16 for simplification purposes). Theprimary mosaiced video streams 211 (A, B and C) received from theprimary SFP units 201 and the internal primary mosaiced video stream areprocessed by the positioning functionality 352 represented in FIG. 10 togenerate the secondary mosaiced video stream 311 (E).

Referring now to FIG. 11, a second implementation of a system comprisingcascaded standardized hot-pluggable transceiving units for providing amultiviewer functionality is represented. As mentioned previously, forillustration purposes, the standardized hot-pluggable transceiving unitsconsist of SFP units; but other types of standardized hot-pluggabletransceiving units may be used for implementing the system.

The system comprises at least one primary SFP unit 400, and a secondarySFP unit 500. For illustration purposes, two primary SFP units 400 arerepresented in FIG. 11. However, the number of primary SFP units 400used by the system may vary. The first layer comprising the at least oneprimary SFP unit 400 is cascaded into the second layer comprising thesecondary SFP unit 500.

Each one of the primary SFP units 400 receives a plurality of sourcevideo streams 401, which are processed by the primary SFP unit 400 togenerate and output a corresponding plurality of scaled video streams411. For illustration purposes, three source video streams 401 arereceived by the first primary SFP unit 400 represented in FIG. 11, andtwo source video streams 401 are received by the second primary SFP unit400 represented in FIG. 11. However, the number of source video streams401 received by each primary SFP unit 400 may vary, and may differ fromone primary SFP unit 400 to another. As will be illustrated later in thedescription, each primary SFP unit 400 implements a scalingfunctionality for generating the outputted scaled video stream 411 basedon the received source video streams 401.

The secondary SFP unit 500 receives the plurality of scaled video stream411 generated and outputted by the at least one primary SFP unit 400.The secondary SFP unit 500 processes the plurality of scaled videostream 411 to generate and output a mosaiced video stream 511. As willbe illustrated later in the description, the secondary SFP unit 500implements a positioning functionality for generating the outputtedmosaiced video stream 511 based on the received scaled video streams411.

Reference is now made concurrently to FIGS. 11, 12A and 12B; where FIG.12A illustrates the scaling functionality implemented by the primary SFPunit(s) 400, and FIG. 12B illustrates the positioning functionalityimplemented by the secondary SFP unit 500.

Referring more particularly to FIGS. 11 and 12A, the source videostreams 401 received by the primary SFP units 400 located on FIG. 7 arerespectively labelled A1, A2, A3 (primary SFP unit 400 on the left ofFIG. 11) and B1, B2 (primary SFP unit 400 on the right of FIG. 11). Thescaling functionality implemented by the primary SFP units 400 scalesthe source video streams A1, A2, A3 and B1, B2 into corresponding scaledvideo streams 411 respectively labelled A′1, A′2, A′3 and B′1, B′2. FIG.12A illustrates a horizontal scaling factor of ½ and a vertical scalingfactor of ½ applied to the source video streams A1, A2, A3 and B1 togenerate the scaled video streams A′1, A′2, A′3 and B′1. FIG. 12A alsoillustrates a horizontal scaling factor of 1 and a vertical scalingfactor of ½ applied to the source video stream B2 to generate the scaledvideo stream B′2. FIG. 12A is for illustration purposes only. Differentvalues of scaling factors may be applied to each one of the source videostreams (e.g. A1, A2, A3 and B1, B2) received by each one of the primarySFP units 400, and the values of the scaling factors may differ from onesource video stream to another.

The scaling functionality implemented by the primary SFP units 400 isfunctionally equivalent to the previously described scalingfunctionality implemented by the primary SFP units 200 of FIG. 7.

Referring more particularly to FIGS. 11 and 12B, the positioningfunctionality of the secondary SFP unit 500 processes the plurality ofscaled video streams 411 (e.g. A′1, A′2, A′3 and B′1, B′2) outputted bythe primary SFP unit(s) 400, to generate the mosaiced video stream 511labelled E. FIG. 12B illustrates the positioning of the five scaledvideo streams A′1, A′2, A′3 and B′1, B′2 outputted by the two primarySFP units 400 of FIG. 11 to generate the corresponding mosaiced videostream E.

The positioning functionality implemented by the secondary SFP unit 500is functionally equivalent to the previously described positioningfunctionality implemented by the secondary SFP unit 300 of FIG. 7.

For instance, FIG. 12B illustrates the mosaiced frames E generated bycombining the scaled video frames A′1, A′2, A′3, B′1, B′2; these scaledvideo frames being respectively positioned at the upper left, upperright, lower right, upper middle and lower left positions withinmosaiced frames E.

Reference is now made concurrently to FIGS. 11, 12A and 13A; where FIG.13A illustrates a first configuration of the primary SFP unit 400. Forillustration purposes, the primary SFP unit 400 of FIG. 13A correspondsto the primary SFP unit 400 on the left of FIG. 11. Furthermore, theprimary SFP unit 400 of FIG. 13A corresponds to the SFP unit 10represented in FIGS. 1 to 6, and comprises the housing 12, the backpanel 16 and the front panel 18.

The primary SFP unit 400 has a rear connector 17 on the back panel 16,and receives the source video streams 401 (A1, A2, A3) via the rearconnector 17.

The primary SFP unit 400 comprises at least one processing unit 450(only one processing unit 450 is represented on FIG. 13A forsimplification purposes). The at least one processing unit 450 executesthe aforementioned scaling functionality 452. The scaling functionality452 processes the received source video streams A1, A2, A3 forrespectively scaling the source video streams A1, A2, A3 into the scaledvideo streams 411 (A′1, A′2, A′3). The scaled video streams A′1, A′2,A′3 are outputted via the rear connector 17.

The primary SFP unit 400 does not have any front connector on the frontpanel 18, since all the data are exchanged via the rear connector 17.Alternatively, the primary SFP unit 400 may have one or more frontconnectors on the front panel 18, for exchanging additional data andperforming a processing of these additional data which is out of thescope of the present disclosure.

Reference is now made concurrently to FIGS. 11, 12A and 13B; where FIG.13B illustrates a second configuration of the primary SFP unit 400. Forillustration purposes, the primary SFP unit 400 of FIG. 13B alsocorresponds to the primary SFP unit 400 on the left of FIG. 11.Furthermore, the primary SFP unit 400 of FIG. 13B corresponds to the SFPunit 10 represented in FIGS. 1 to 6, and comprises the housing 12, theback panel 16 and the front panel 18.

The primary SFP unit 400 has a rear connector 17 on the back panel 16and a front connector 20 on the front panel 18. The primary SFP unit 400receives the source video streams 401 (A1, A2, A3) via the frontconnector 20.

The primary SFP unit 400 comprises at least one processing unit 450(only one processing unit 450 is represented on FIG. 13B forsimplification purposes). The at least one processing unit 450 executesthe aforementioned scaling functionality 452. The scaling functionality452 processes the received source video streams A1, A2, A3 forrespectively scaling the source video streams A1, A2, A3 into the scaledvideo streams 411 (A′1, A′2, A′3). The scaled video streams A′1, A′2,A′3 are outputted via the rear connector 17. Alternatively, the scaledvideo streams A′1, A′2, A′3 are outputted via the front connector 20(this configuration is not represented in the Figures for simplificationpurposes).

The primary SFP unit 400 may have more than one front connector on thefront panel 18 (this configuration is not represented in the Figures forsimplification purposes). The reception of the source video streams 401is spread across the plurality of front connectors. For example, thefront connector 20 receives the source video streams A1 and A2, and asecond front connector not represented in FIG. 13B receives the sourcevideo stream A3. Alternatively, the front connector 20 receives all thesource video streams A1, A2, A3 as illustrated in FIG. 13B, and a secondfront connector not represented in FIG. 13B outputs the scaled videostreams A′1, A′2, A′3.

In a particular embodiment, the primary SFP unit 400 has four frontconnectors (Quad SFP) of electrical or optical type with an aggregatebandwidth of at least 40 Gbps.

Reference is now made concurrently to FIGS. 11, 12B and 14A; where FIG.14A illustrates a first configuration of the secondary SFP unit 500. Thesecondary SFP unit 500 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 500 has a rear connector 17 on the back panel 16,and receives the scaled video streams 411 (A′1, A′2, A′3 and B′1, B′2respectively generated by the two primary SFP units 400 of FIG. 11) viathe rear connector 17.

The secondary SFP unit 500 comprises at least one processing unit 550(only one processing unit 550 is represented on FIG. 14A forsimplification purposes). The at least one processing unit 550 executesthe aforementioned positioning functionality 552.

The positioning functionality 552 processes the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) for mosaicing the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) into the mosaiced video stream 511 (E). Themosaiced video stream 511 (E) is outputted via the rear connector 17.

The secondary SFP unit 500 does not have any front connector on thefront panel 18, since all the data are exchanged via the rear connector17. Alternatively, the secondary SFP unit 500 may have one or more frontconnectors on the front panel 18, for exchanging additional data andperforming a processing of these additional data which is out of thescope of the present disclosure.

Reference is now made concurrently to FIGS. 11, 12B and 14B; where FIG.14B illustrates a second configuration of the secondary SFP unit 500.The secondary SFP unit 500 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 500 has a rear connector 17 on the back panel 16,and a front connector 20 on the front panel 18. The secondary SFP unit500 receives the scaled video streams 411 (A′1, A′2, A′3 and B1, B′2respectively generated by the two primary SFP units 400 of FIG. 11) viathe rear connector 17.

The secondary SFP unit 500 comprises at least one processing unit 550(only one processing unit 550 is represented on FIG. 14A forsimplification purposes). The at least one processing unit 550 executesthe aforementioned positioning functionality 552.

The positioning functionality 552 processes the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) for mosaicing the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) into the mosaiced video stream 511 (E). Themosaiced video stream 511 (E) is outputted via the front connector 20.

The secondary SFP unit 500 may have more than one front connector on thefront panel 18, for exchanging additional data and performing aprocessing of these additional data which is out of the scope of thepresent disclosure.

Reference is now made concurrently to FIGS. 11, 12B and 14C; where FIG.14C illustrates a third configuration of the secondary SFP unit 500. Thesecondary SFP unit 500 corresponds to the SFP unit 10 represented inFIGS. 1 to 6, and comprises the housing 12, the back panel 16 and thefront panel 18.

The secondary SFP unit 500 has a rear connector 17 on the back panel 16and a front connector 20 on the front panel 18. The secondary SFP unit500 receives the scaled video streams 411 (A′1, A′2, A′3 and B′ 1, B′2respectively generated by the two primary SFP units 400 of FIG. 11) viathe front connector 20.

The secondary SFP unit 500 comprises at least one processing unit 550(only one processing unit 550 is represented on FIG. 14C forsimplification purposes). The at least one processing unit 550 executesthe aforementioned positioning functionality 552.

The positioning functionality 552 processes the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) for mosaicing the scaled video streams 411(A′1, A′2, A′3 and B′1, B′2) into the mosaiced video stream 511 (E). Themosaiced video stream 511 (E) is outputted via the rear connector 17.Alternatively, the mosaiced video stream 511 (E) is outputted via thefront connector 20 (this configuration is not represented in the Figuresfor simplification purposes).

The secondary SFP unit 500 may have more than one front connector on thefront panel 18 (this configuration is not represented in the Figures forsimplification purposes). The reception of the scaled video streams 411is spread across the plurality of front connectors. For example, thefront connector 20 receives the scaled video streams A′1, A′2, A′3, anda second front connector not represented in FIG. 14C receives the scaledvideo streams B′1, B′2. Alternatively, the front connector 20 receivesall the scaled video streams A′1, A′2, A′3 and B′1, B′2 as illustratedin FIG. 14C, and a second front connector not represented in FIG. 14Coutputs the secondary mosaiced video stream 511 (E).

Referring more specifically to FIG. 11, in an alternative implementationof the system, the functionalities of the secondary SFP unit 500 areimplemented by a generic computing device (such as a computer, a server,a networking equipment, etc.) instead of a SFP unit.

Referring more specifically to FIGS. 11 and 17, another alternativeimplementation of the system consists of the following. One of theprimary SFP units 400 represented in FIG. 11 also implements thefunctionalities of the secondary SFP unit 500 represented in FIG. 11.The implementation represented in FIG. 17 is similar to theimplementation represented in FIG. 16, with the exception that theprimary SFP units of FIG. 16 implement a pre-positioning functionality,while the primary SFP units of FIG. 17 do not implement apre-positioning functionality.

FIG. 17 represents the SFP unit 500′ combining the functionalities of aprimary SFP unit (scaling functionality 452 represented in FIG. 13A) anda secondary SFP unit (positioning functionality 552 represented in FIG.14A). The SFP unit 500′ receives the source video streams 401, which areprocessed by the scaling functionality 452 represented in FIG. 13A togenerate internal scaled video streams (not represented in FIG. 17 forsimplification purposes). The scaled video streams 411 (A′1, A′2 andA′3) received from the primary SFP unit(s) 401 and the internal scaledvideo streams are processed by the positioning functionality 452represented in FIG. 13A to generate the mosaiced video stream 511 (E).

Reference is now made concurrently to FIGS. 9A-B, 10A-C, 13A-B and14A-C.

The scaling functionality (252 or 452), the pre-positioningfunctionality 254, and the positioning functionality (352 or 552) areimplemented by a software executed by the corresponding processing units(250, 350, 450 or 550). Alternatively, the scaling functionality (252 or452), the pre-positioning functionality 254, and the positioningfunctionality (352 or 552) are implemented by dedicated hardwarecomponent(s) of the corresponding processing units (250, 350, 450 or550), for instance one or several Field-Programmable Gate Array (FPGA).A combination of software and dedicated hardware component(s) may alsobe used for implementing these functionalities.

The processing unit 250 (or 450) of the primary SFP unit 200 (or 400)may execute additional functionalities, prior to or after executing thescaling functionality 252 (or 452). Some of the additionalfunctionalities may be executed by another processing unit (notrepresented in the Figures) of the primary SFP unit 200 (or 400),instead of being also executed by the processing unit 250 (or 450).

For example, the processing unit 250 (or 450) also executes ade-interlacing functionality (not represented in the Figures forsimplification purposes). At least one of the source video streams 201(or 401) received by the primary SFP unit 200 (or 400) is interlaced,and the corresponding scaled video stream generated by the primary SFPunit 200 (or 400) is de-interlaced. More specifically, each video frametransported by one of the source video streams 201 (or 401) isinterlaced, and each corresponding scaled video frame of thecorresponding scaled video stream is de-interlaced. The operationconsisting in de-interlacing a video frame is well known in the art. Thereceived source video stream 201 (or 401) is first de-interlaced by thede-interlacing functionality, and then scaled by the scalingfunctionality 252 (or 452), to generate a de-interlaced scaled videostream. Alternatively, the received source video stream 201 (or 401) isfirst scaled by the scaling functionality 252 (or 452), and thende-interlaced by the de-interlacing functionality, to generate thede-interlaced scaled video stream.

In another example, at least one of the source video streams 201 (or401) received by the primary SFP unit 200 (or 400) is in a HighDefinition (HD) format with a higher resolution (e.g. 1080p), and thecorresponding scaled video stream is in a HD format with a lowerresolution (e.g. 720p or 1080i). The processing unit 250 (or 450)further performs a conversion of the higher resolution HD format of thesource video stream into the lower resolution HD format of thecorresponding scaled video stream. The conversion from the higherresolution HD format to the lower resolution HD format can be performedbefore or after executing the scaling functionality 252 (or 452).

The processing unit 350 (or 550) of the secondary SFP unit 300 (or 500)may also execute additional functionalities, prior to or after executingthe positioning functionality 352 (or 552). Some of the additionalfunctionalities may be executed by another processing unit (notrepresented in the Figures) of the secondary SFP unit 300 (or 500),instead of being also executed by the processing unit 350 (or 550).

For example, the processing unit 350 (or 550) also executes apost-production functionality (not represented in the Figures forsimplification purposes). The post-production functionality consists inadding post-production data to the secondary mosaiced video stream 311of FIGS. 10A-B (or the mosaiced video stream 511 of FIGS. 14A-B) beforeit is outputted. The post-production data include at least one of thefollowing: a sur-imposed text, a sur-imposed icon, a sur-imposed image,etc. The post-production data convey information relative to errordetection (e.g. frame blank, frame freeze, etc.), origin of the sourcevideo streams 201 (or 401), etc.

The rear connector 17 of the SFP units 200 (or 400) and 300 (or 500) isan electrical connector adapted for receiving and outputting electricalsignals transporting the video streams.

The front connector(s) (e.g. 20) of the SFP units 200 (or 400) and 300(or 500) is an electrical connector adapted for receiving and/oroutputting electrical signals transporting the video streams over anelectric cable connected to the front connector. Alternatively, thefront connector(s) (e.g. 20) of the SFP units 200 (or 400) and 300 (or500) is an optical connector adapted for receiving and/or outputtingoptical signals transporting the video streams over an optical cableconnected to the front connector.

The video streams are transported by IP flows, which have a physicallayer adapted for the transport of IP packets, such as Ethernet,Synchronous Optical Networking (SONET)/Synchronous Digital Hierarchy(SDH), etc. An IP flow is well known in the art. It consists in asequence of IP packets from a source to a destination, delivered viazero, one or more intermediate routing (e.g. a router) or switchingequipment (e.g. an IP switch). Several protocol layers are involved inthe transport of the IP packets of the IP flow, including a physicallayer (e.g. optical or electrical), a link layer (e.g. Media AccessControl (MAC) for Ethernet), an Internet layer (e.g. IPv4 or IPv6), atransport layer (e.g. User Datagram Protocol (UDP)), and one or moreapplication layers ultimately embedding a video payload (the videoframes transported by a video stream). Optionally, the applicationlayers also ultimately embed an audio payload and/or a metadata payload.The IP flow provides end-to-end delivery of the video payload over an IPnetworking infrastructure. The IP flow may be unicast or multicast.

The video payload transported by the IP flows may consist of an SDIpayload, which is compliant with the SDI standard. It encompassesseveral variants of the SDI standard, including for example SD-SDI,HD-SDI, ED-SDI, 3G-SDI, 6G-SDI, 12G-SDI, etc.; which have all beenstandardized by the Society of Motion Picture & Television Engineers(SMPTE) organization. An SDI payload comprises a video payload carryinga video component of a source SDI signal. The SDI payload generally alsocomprises at least one additional payload, such as an audio payload forcarrying an audio component of the source SDI signal and/or a metadatapayload for carrying a metadata component of the source SDI signal.

Furthermore, the SDI video payload may be compliant with at least one ofthe following SMPTE standards: the SMPTE 2022-5 standard, the SMPTE2022-6 standard, and the SMPTE 2022-7 standard. These three standardsare used singly or in combination for transporting SDI payloads (e.g. aSDI video payload and a corresponding SDI audio payload) over IP. TheSMPTE 2022-5 standard provides a Forward Error Correction (FEC) schemefor compensating potential IP packet losses of an IP flow transportingan SDI payload, since IP networks do not provide a guaranteed deliveryof all transmitted IP packets. The SMPTE 2022-6 standard providestransport of SDI payloads via the Real-time Transport Protocol (RTP). Italso provides an additional protocol layer on top of the RTP layer: theHigh-Bitrate Media Transport Protocol (HBRMT) protocol layer, whichsupports a high-precision clock and extra metadata. The SMPTE 2022-7standard provides seamless protection switching to an IP flowtransporting an SDI payload, by sending two matching streams of IPpackets from a source to a destination over different paths, and havethe receiver switch automatically between them. The SDI video payloadmay also be compliant with the SMPTE 2110 standard

Other types of video payloads can be transported by the IP flows, suchas for example a High-Definition Multimedia Interface (HDMI) videopayload, etc.

In some cases, some of the front connectors (e.g. 20) of the SFP units200 (or 400) and 300 (or 500) are not adapted to receive and/or outputvideo streams transported by an IP flow. These front connectors (e.g.20) are adapted to receive and/or output a native video signaltransporting the video streams. For example, the native video signal isgenerated by a source video equipment and transported as is from thesource video equipment to the SFP unit, without conversion into an IPflow. In another example, the native video signal is used by adestination video equipment and transported as is from the SFP unit tothe destination video equipment, without conversion into an IP flow. Forinstance, some of the front connectors (e.g. 20) consist of SDIconnectors adapted to receive and/or output SDI video signals. SDIconnectors are a family of digital video interfaces using one or morecoaxial cables with Bayonet Neill-Concelman (BNC) connectors.

The operations of at least one of the scaling functionality 252 (or452), the pre-positioning functionality 254 (or 454) and the positioningfunctionality 352 (or 552) can be remotely controlled.

With respect to the scaling functionality (e.g. 252), the primary SFPunit (e.g. 200) receives a control message from a third-party computingdevice (not represented in the Figures). The control message comprisesat least one scaling ratio and an identification of a correspondingsource video stream (e.g. A1).

For example, a control message comprises an identification of a sourceIP flow (e.g. source and destination IP addresses, source anddestination ports) transporting one of the source video streams (e.g.A1) and a scaling ratio to apply to this source video stream (e.g. A1).Upon reception of this command, the scaling functionality (e.g. 252)starts generating the corresponding scaled video stream (e.g. A′1) inaccordance with the scaling factor provided in the control message.

At the beginning of the operations of the primary SFP unit (e.g. 200),the control message comprises an identification of all the source videostreams (e.g. A1, A2, A3, A4) and corresponding scaling ratios torespectively apply to these source video streams, to generate thecorresponding scaled video streams (e.g. A′1, A′2, A′3, A′4). Later on,an update control message may be received, to modify one or more scalingratios applied to one or more of the source video streams (e.g. only A1and A3). If several source video streams have the same scaling ratio(e.g. A1, A2, A2. A4 in FIG. 8A), the control message comprises thisparticular scaling ratio associated to all the source video streamshaving this particular scaling ratio.

With respect to the pre-positioning functionality (e.g. 254), theprimary SFP unit (e.g. 200) receives a control message from athird-party computing device (not represented in the Figures). Thecontrol message comprises an identification of each of the scaled videostreams (e.g. A′1, A′2, A′3, A′4), and their respective position withinthe primary mosaiced video stream (e.g. A). The identification of thescaled video streams (e.g. A′1, A′2, A′3, A′4) simply consists in theidentification of the corresponding source video streams (e.g. A1, A2,A3, A4), the processing unit 250 storing an association between thesource video streams (e.g. A1, A2, A3, A4) and the scaled video streams(e.g. A′1, A′2, A′3, A′4). The same control message may be used forcontrolling the scaling functionality (e.g. 252) and the pre-positioningfunctionality (e.g. 254). During operations, an update control messagemay be received, to modify one or more positions applied to one or moreof the scaled video streams (e.g. only A′1 and A′3). The update controlmessage may affect only the operations of the pre-positioningfunctionality (e.g. 254), of affect simultaneously the operations of thescaling functionality (e.g. 252) and the pre-positioning functionality(e.g. 254). The control message may also include characteristics of theprimary mosaiced video streams (e.g. A) generated by the primary SFPunits (e.g. 200). For example, these characteristics comprisecharacteristics of an IP flow (e.g. source and destination IP addresses,source and destination ports) transporting the primary mosaiced videostreams (e.g. A).

With respect to the positioning functionality (e.g. 352), it iscontrolled in a manner similar to the pre-positioning functionality(e.g. 254). For example, the secondary SFP unit (e.g. 300) receives acontrol message from a third-party computing device (not represented inthe Figures). The control message comprises an identification of each ofthe primary mosaiced video streams (e.g. A, B, C, D), and theirrespective position within the secondary mosaiced video stream (e.g. E).During operations, an update control message may be received, to modifyone or more positions applied to one or more of the scaled video streams(e.g. only A and C). The control message may also includecharacteristics of the secondary mosaiced video stream (e.g. E)generated by the secondary SFP unit (e.g. 300). For example, thesecharacteristics comprise characteristics of an IP flow (e.g. source anddestination IP addresses, source and destination ports) transporting thesecondary mosaiced video stream (e.g. E).

The third-party computing device for controlling the operations of thescaling functionality (e.g. 252) includes a user interface, allowing auser to enter user commands. The user commands are processed by thethird-party computing device to generate the control message transmittedto the primary SFP units (e.g. 200). The control message can betransported via the IP protocol. Upon reception of the control message(e.g. via the rear connector 17 of the primary SFP unit 200), theprocessing unit (e.g. 250) interprets the received control message, andcontrols the operations of the scaling functionality (e.g. 252)accordingly. The control message may be compliant with a standardizedControl Plane Signaling protocol, such as the Simple Network ManagementProtocol (SNMP), OpenFlow, etc. Alternatively, the control message iscompliant with a proprietary Control Plane Signaling protocol. The samemechanism is used for controlling the operations of the pre-positioningfunctionality (e.g. 254) and positioning functionality (e.g. 352).

Reference is now made concurrently to FIGS. 7, 9A, 10A and 15; whereFIG. 15 represents an exemplary use case for the usage of the systemdescribed in the present disclosure for providing a multiviewerfunctionality through cascaded standardized hot-pluggable transceivingunits (and more specifically through cascaded SFP units in the presentexample). For illustration purposes, this exemplary use case correspondsto the system described in relation to FIG. 7. However, a person skilledin the art could easily adapt it to the system described in relation toFIG. 11.

The first layer of cascaded SFP units consisting of the four primary SFPunits 200 is inserted in a chassis of an IP switch 100. The second layerof cascaded SFP units consisting of the secondary SFP unit 300 is alsoinserted in the chassis of the IP switch 100. As mentioned previously inthe description, the number of primary SFP units 200 inserted in thechassis of the IP switch 100 may vary.

The IP switch 100 comprises a processing unit 110 implementing anetworking functionality 115 (e.g. switching and/or routing). Theprocessing unit 110 receives data packets through various networkinginterfaces of the IP switch 100, and the networking functionality 115processes the received data packets to forward these data packets thoughone of the interfaces of the IP switch 100, as is well known in the art.Other types of equipment may be used in place of the IP switch 100, suchas routers, gateways, video servers, etc. The only requirement on theseequipment is that they include a chassis adapted for receiving the SFPunits 200 and 300.

The exemplary use case represented in FIG. 15 corresponds to theconfiguration represented in FIGS. 9A and 10A. The IP switch 100includes an Ethernet port 120 for receiving the source video streams 201generated by one or more video sources 600. The source video streams 201are transported by IP flows through an IP networking infrastructurebetween the video sources 600 and the IP switch 100.

Examples of video sources 600 include professional video recorders forthe film industry, security cameras, television broadcasting equipment,etc. The video source 600 may directly generate an IP flow fortransporting the source video streams 201. Alternatively, the videosource 600 generates a video signal transporting the source videostreams 201, which is converted by a video gateway (not represented inFIG. 15) into a corresponding IP flow transporting the source videostreams 201.

The source video streams 201 are received through the Ethernet port 120,and forwarded to the primary SFP units 200 by the networkingfunctionality 115, via the rear connectors 17 of the SFP units 200.

The primary mosaiced video streams 211 generated by the primary SFPunits 200 are transmitted to the networking functionality 115, via therear connectors 17 of the primary SFP units 200. The primary mosaicedvideo streams 211 are forwarded to the secondary SFP unit 300 by thenetworking functionality 115, via the rear connector 17 of the SFP unit300.

The secondary mosaiced video stream 311 generated by the secondary SFPunit 300 is transmitted to the networking functionality 115, via therear connector 17 of the secondary SFP unit 300. The secondary mosaicedvideo stream 311 is forwarded to a video receiver 700 by the networkingfunctionality 115, via the Ethernet port of the IP switch 100.

The secondary mosaiced video stream 311 is transported by an IP flowthrough an IP networking infrastructure between the IP switch 100 andthe video receiver 700. The video receiver 700 may be any type ofequipment comprising a screen 700 for displaying the secondary mosaicedvideo stream 311. The frames of the secondary mosaiced video stream 311displayed on the screen 700 are illustrated in FIG. 8C. The secondarymosaiced video stream 311 may be transmitted to several video receivers700, for instance via a multicast IP flow as is well known in the art.

Another exemplary configuration (not represented in FIG. 15) correspondsto the configuration represented in FIGS. 9B and 10A. The source videostreams 201 generated by the one or more video sources 600 are receivedvia the front connectors 20 of the primary SFP units 200, instead of theEthernet port 120.

Still another exemplary configuration (not represented in FIG. 15)corresponds to the configuration represented in FIGS. 9B and 10B. Thesource video streams 201 generated by the one or more video sources 600are received via the front connectors 20 of the primary SFP units 200,instead of the Ethernet port 120. The secondary mosaiced video stream311 generated by the secondary SFP unit 300 is outputted via the frontconnector 20 of the secondary SFP unit 300, instead of the Ethernet port120.

Yet another exemplary configuration (not represented in FIG. 15)corresponds to the configuration represented in FIGS. 9A and 10B. Thesecondary mosaiced video stream 311 generated by the secondary SFP unit300 is outputted via the front connector 20 of the secondary SFP unit300, instead of the Ethernet port 120.

In some of the aforementioned configurations, the SFP units 200 and/or300 are only physically connected to the IP switch 100 via theirrespective rear connector 17, but do not exchange data with theprocessing unit 115 of the IP switch 100. The exchange of data (at leastsome of the source video streams 201, the primary mosaiced video streams201, and the second mosaiced video stream 311) is performed via thefront connector(s) (e.g. 20).

In some of the aforementioned configurations, the SFP units 200 and/or300 only exchange data (at least some of the source video streams 201,the primary mosaiced video streams 201, and the second mosaiced videostream 311) with the processing unit 115 of the IP switch 100 via theirrespective rear connector 17. There is no exchange of data via the frontconnector(s) (e.g. 20), and some SFP units may have no frontconnector(s) at all.

The IP switch 100 is capable of performing layer 3 and/or layer 2forwarding of IP packets, as is well known in the art. The term IPswitch is used generically, and may encompass switches, routers, etc. Arouter generally has more sophisticated routing capabilities than aswitch.

However, the IP switch 100 is a highly specialized equipment, optimizedfor performing switching and/or routing of IP packets in a veryeffective manner. Therefore, the IP switch 100 generally does not have anative scaling functionality, pre-positioning functionality, orpositioning functionality. The software of the IP switch 100 may beupgraded to implement at least some of these functionalities, at therisk of downgrading the performances of its switching and/or routingfunctionalities, and at a potentially prohibitive cost. Therefore, theuse of the primary SFP units 200 and secondary SFP unit 300 is a simple,cost effective way to upgrade the IP switch 100 with the cascadedscaling/pre-positioning and positioning functionalities, withoutdowngrading the intrinsic capabilities of the IP switch 100.

The transport of video payloads on an IP networking infrastructure has amajor impact in terms of network load, which may result in congestion ofthe IP network, delays in the delivery of IP packets transporting avideo payload, or even loss of packets (with an optional retransmissionof the lost packets). For instance, a single video IP flow transportinga video payload requires a bandwidth of 1.5 Gbps in the case of a 720por 1080i High Definition (HD) format, and a single video IP flowtransporting a video payload requires a bandwidth of 3 Gbps in the caseof a 1080p HD format. Since video is generally time sensitive, delayshave a major impact on the perceived quality of a video transmission.Existing technologies, such as Qualify of Service (QoS) policies can beused to guarantee the delivery of a video IP flow within acceptableboundaries in terms of delays. However, enforcing a QoS policy for avideo IP flow increases the cost (a premium fee needs to be paid forbenefiting of a QoS policy prioritizing the IP packets of a particularIP flow) and/or complexity of delivery (additional control signaling isused to enforce the QoS policy).

If the source video streams 201 respectively transport a HD videopayload requiring a bandwidth of 1.5 Gbps, a total bandwith of 24 Gbpsis necessary for transporting the corresponding 16 source video streams201 (represented in FIG. 7) on the IP networking infrastructure.However, the secondary mosaiced video stream 311 projected on the screen710 of the video receiver 700 is equivalent to four HD video payloads(because of the ¼ scaling factor applied to the source video streams201), which only requires a bandwidth of 6 Gbps when transported on theIP networking infrastructure. Thus, in this exemplary use case, byperforming the scaling operation at the IP switch 100 via the primarySFP units 200 instead of performing it at the final video receiver 700,18 Gbps of bandwidth are saved in the IP networking infrastructurebetween the IP switch 100 and the final video receiver 700. Furthermore,performing the pre-positioning and positioning operations at the IPswitch 100 via the primary SFP units 200 and secondary SFP unit 200,instead of performing it at the final video receiver 700, drasticallyreduces the number of video streams (1 instead of 16) transported on theIP networking infrastructure between the IP switch 100 and the finalvideo receiver 700.

Although the present disclosure has been described hereinabove by way ofnon-restrictive, illustrative embodiments thereof, these embodiments maybe modified at will within the scope of the appended claims withoutdeparting from the spirit and nature of the present disclosure.

What is claimed is:
 1. A system comprising: at least one standardizedhot-pluggable transceiving units respectively comprising: a housinghaving specific standardized dimensions and adapted to being insertedinto a chassis of a hosting unit; a plurality of connectors, eachconnector receiving at least one distinct source video stream; at leastone processing unit in the housing for: scaling the source video streamsreceived by the plurality of connectors into a corresponding pluralityof scaled video streams; mosaicing the plurality of scaled video streamsinto a mosaiced video stream; and outputting the mosaiced video streamvia one of the plurality of connectors.
 2. The system of claim 1,wherein each source video stream transports a plurality of source videoframes, each corresponding scaled video stream transports a plurality ofscaled video frames, and the scaling comprises applying a scaling ratioto the plurality of source video frames to generate the correspondingplurality of scaled video frames.
 3. The system of claim 1, wherein thescaling of the plurality of source video streams into a correspondingplurality of scaled video streams consists of a temporal scaling, andeach one of the plurality of scaled video streams has a frame rate lowerthan the corresponding source video stream.
 4. The system of claim 1,wherein mosaicing the plurality of scaled video streams into themosaiced video stream comprises combining scaled video framesrespectively transported by the scaled video streams at respective givenpositions within mosaiced video frames transported by the mosaiced videostream.
 5. The system of claim 1, wherein the at least one transceivingunit receives a control message from a third-party computing device, thecontrol message comprising at least one of the following: a scalingratio associated to each one of the source video streams received by thetransceiving unit, and a position associated to each one of the scaledvideo streams generated by the transceiving unit.
 6. The system of claim1, wherein one of the plurality of connectors is a rear connectorlocated on a back panel of the at least one transceiving unit, themosaiced video streams being outputted via the rear connector.